CHZ

Histone chaperone domain CHZ

SMART accession number:

SM01082

Description:

This domain is highly conserved from yeasts to humans and is part of the chaperone protein HIRIP3 in vertebrates which interacts with the H3.3 chaperone HIRA, implicated in histone replacement during transcription. N- and C- termini of Chz family members are relatively divergent but do contain similar acidic stretches rich in Glu/Asp residues, characteristic of all histone chaperones (PUBMED:17289584).

This domain is highly conserved from yeasts to humans and is part of the chaperone protein HIRIP3 in vertebrates which interacts with the H3.3 chaperone HIRA, implicated in histone replacement during transcription. N- and C- termini of Chz family members are relatively divergent but do contain similar acidic stretches rich in Glu/Asp residues, characteristic of all histone chaperones [(PUBMED:17289584)].

The histone variant H2AZ marks nucleosomes flanking the promoters of mostgenes of budding yeast. The incorporation of H2AZ into chromatin isdependent on the SWR1 complex, which catalyses the replacement ofconventional histone H2A with H2AZ. In cells, the pool of unincorporatedhistone H2AZ has previously been found in association with Nap1, achaperone for conventional histone H2A-H2B. Here, we report the discoveryof Chz1, a histone chaperone that has preference for H2AZ and can alsodeliver a source of the histone variant for SWR1-dependent histonereplacement. Bacterially expressed Chz1 forms a heterotrimer withH2AZ-H2B, stabilizing the association of the histone dimer. We haveidentified a conserved motif important for histone variant recognitionwithin the H2AZ-interacting domain of Chz1. The presence of this motif inother metazoan proteins suggests that H2AZ-specific chaperones may bewidely conserved.